The disclosed subject matter relates generally to communication systems, and, more particularly, to wireless communication systems.
Conventional wireless communication systems use a network of base stations or other access nodes to provide wireless connectivity to a large and often mobile population of access terminals. Each access terminal can be identified to the wireless communication system by an identifier that is permanently assigned or “burned in” to the mobile unit. For example, implementations of WiMAX release 1 that are based on the standards and protocols defined by IEEE 802.16e (2009) use a constant 48-bit mobile station identifier (MS-ID) to identify the access terminals in the network. The MS-ID is typically installed or programmed by the manufacturer of the access terminal in the form of media access control (MAC) identifier. For another example, wireless communication systems that operate according to the Global System for Mobile communications (GSM) and/or Universal Mobile Telecommunication Services (UMTS) standards and/or protocols may use a 64-bit International Mobile Subscriber Identity (IMSI) to identify each mobile unit or access terminal
The conventional mobile station identifier is used to identify the access terminal within the network and over the air. For example, the mobile station identifier can be included in headers of messages that are transmitted within the network such as messages transmitted over the R6 network interfaces between base stations and access serving network gateways (ASN-GWs), over R3 network interface between the ASN-GW and the AAA server, over the R8 network interfaces between two neighboring base stations, over the R4 interfaces between two ASN-GWs, and the like. For another example, access terminals can be paged over the air by transmitting a hashed value derived from the identifier, e.g., a 24-bit hash of a 48-bit identifier can be used to page access terminals. The mobile station identifier can also be used directly as a pointer to the mobile station context information stored at one or more network nodes that are involved in a particular call associated with a particular mobile station state.
Access terminals can also be associated with different identifiers in different circumstances. For example, WiMAX networks that operate according to IEEE 802.16m standards and/or protocols may identify access terminals using a set of identification numbers that range in length from 10 bits to 72 bits depending on the operational state of the access terminal Consequently, the identifier that is used by the network and over the air varies as the operational mode changes, e.g., as the access terminal performs initial network entry, gets fully authenticated and active and then shifts between sleeping, dormant, idle, active, or other operational states. The wireless communication system must therefore maintain awareness of the appropriate value of the identifier used to identify the access terminal in over the air messages as well as messages exchanged within the network such as messages transmitted over the R3, R4, R6, R8 and other interfaces. Managing the various identifiers is further complicated by the presence of both legacy access devices that use a single constant identifier such as the 48-bit mobile station identifier and advanced access devices that use a set of identification numbers.